1. Field of the Invention
The present invention generally relates to an inkjet printing system, and in particular to an ink consumption detection method and system for an inkjet printer.
2. Description of the Related Art
An inkjet printer is provided with a print head having an array or nozzles which selectively eject ink to form a pattern of dots on the printing medium depending on print data. Since the ink is stored in an ink reservoir, it is important to check the ink level of the ink reservoir to avoid deterioration of print quality.
A conventional ink level check apparatus has been disclosed in Japanese Patent Unexamined Publication No. 4-316856. According to the conventional apparatus, each time ink suction is performed for nozzle cleaning, the amount of suctioned ink is represented on the basis of the number of dots. The number of dots corresponding to the amount of suctioned ink is added to the number of printed dots which were actually printed for one line. The ink level of the ink reservoir is checked by calculating a ratio of the total number of actually-printed and represented dots to the possible number of dots corresponding to the full capacity of the ink reservoir.
However, the dot count process forms an increasing proportion of the print control process as the resolution of the printer increases. Therefore, the interval from the time the print of the previous line is ended to the time the current line is started becomes longer, resulting in reduced speed of printing.
Further, only the amount of suctioned ink is counted. Therefore, the reliability of the ink level check is not enough. If all operations leading to ink consumption are taken into account, the dot count process would cause the speed of printing to be further reduced.